CN1006773B

CN1006773B - Multi-layered vessels and method for molding the same

Info

Publication number: CN1006773B
Application number: CN86102410A
Authority: CN
Inventors: 中村喜则; 折元宏行; 佐藤晃一
Original assignee: Nissei ASB Machine Co Ltd
Current assignee: Nissei ASB Machine Co Ltd
Priority date: 1985-04-12
Filing date: 1986-04-12
Publication date: 1990-02-14
Also published as: ES553938A0; KR860008017A; JPH053376B2; US4774047A; ES8704382A1; AU588581B2; CN86102410A; NZ215789A; EP0199633A2; US4743479A; AU5591186A; EP0199633A3; CA1271435A; EP0199633B1; JPS61235126A; DE3688686T2; DE3688686D1; BR8601821A; KR940005636B1

Abstract

The present invention provides a multi-layered vessel whose sectional construction comprises at least a triple-layer obtained by blow or orientation blow molding an injection molded multi-layered parison, comprising a first resin forming a body, and a second resin having gas barrier properties or heat resistance more than that of the first resin, the second resin being present as an intermediate layer of the body within the first resin, the intermediate layer being smaller in wall thickness than an outer layer of the body and being one-sided toward the outer layer, the first layer being defined into an inner layer and an outer layer by the intermediate layer, the wall thicknesses of the outer layer and the inner layer being in the ratio of outer layer to inner layer, 1:1.50 or more, preferably, in the range of 1:3.50.

Description

Multi-layered vessels and method for molding the same

The invention relates to a kind of container of multilayer, the section structure of the container of this synthetic resin has three layers at least, is used for carbonated beverage or fruit juice.

The plastic packaging containers made from blowing or orientation blow mollding method has in light weight and is not afraid of the advantage of falling, but its resistance to heat and trapping performance are not as glass container.When this container is used for dixie cup,, must do further improvement to this container for the seepage of the fruit juice, oxygen, carbonic acid or other things that are suppressed at can under the hot conditions.

From above-mentioned reason, developed and a kind of laminated vessel that has three layers at least, form in the used resin of this vessel (such as polyethylene terephthalate), adopted another resin as interlayer, this can remedy the shortcoming of the sort of resin of saying the front.As the material of other several interlayers, can adopt ethylene-vinyl alcohol copolymer and polycarbonate acid amides etc., the former has good trapping performance, and the latter has resistance to heat.

The container of this multiple-structure can be produced with blowing or orientation blow mollding method with the multilayer parison of an extrusion forming or injection mo(u)lding, just identical with situation at monolayered vessel, and will be in the middle of the resin that forms vessel or the inside add the last layer interlayer.When interlayer is added in the resin centre of vessel, the internal layer that is separated by interlayer does not have any difference with outer on thickness, but when the inboard was leaned in the position of interlayer, the internal layer of container was just different with outer field thickness, at this moment, the thickness of internal layer is much thinner than skin.

In laminated vessel, the thickness size of each layer depends on that the thickness of the parison at the bottom of the band of the multilayer of producing with pressing method or injection moulding process distributes, and the thickness proportion of each layer of parison will become each layer thickness allocation proportion of container, does not have what variation in the course of processing.

When the parison at the bottom of the blowing sandwich tape, use a double-deck nozzle, the exeterior passageway of nozzle communicates with the outlet of nozzle, the internal channel of nozzle then is connected with the most not end of exeterior passageway, as U.S. Patent No. 4,174, proposed in 413 like that, simultaneously, respectively by this exeterior passageway and internal channel with first kind of resin and second kind of resin injection among cavity, first kind of resin forms vessel, and second kind of resin forms interlayer.The thickness of interlayer can change with the amount of two kinds of resins, but always this interlayer inwards lateral deviation move, therefore, the thickness of internal layer is always thinner.

Resemble ethylene-vinyl alcohol copolymer (EVOH), this resinoid such as polyamide (PA), moisture content absorb to such an extent that the seepage of oxygen, carbonic acid etc. is terrible more more at most.On the other hand, be used as the Polyester resin of the biaxial orientation of carbonated drink bottle, littler to the penetrablility of water vapour than the top resin of saying, but the penetrablility of water vapour is subjected to the influence of the thickness of general resin again.

So, in the less laminated vessel of internal layer wall thickness, both having made the resin that forms containers is the polyethylene terephthalate of biaxial orientation, owing to absorb the influence of moisture content, the trapping performance of interlayer also can reduce greatly, and the seepage of oxygen and carbonic acid can increase to some extent.Therefore, this container is not suitable for beer, carbonated drink and similar products, because these things all need to store long time, in addition, want to adorn the Food ﹠ Drink that those are afraid of that aerobic air infiltrations leak with this container, both made be laminated vessel also further improve its trapping performance.

Equally, in order to increase the resistance to heat of container, both having made second kind of resin as interlayer is a kind of heat-resisting resin, does not wish that also the thickness of internal layer is too thin, and should make the thickness of internal layer thicker as much as possible.But, up to the present, layer thickness is not greater than three layers of heat-resisting container of outer layer thickness in also not having to manufacture.

The existing problem of being said above the present invention will solve just of relevant laminated vessel.An object of the present invention is to provide a kind of later-model laminated vessel, or a kind of interior layer thickness with good heat resistance energy compares the big laminated vessel of interior layer thickness of structure in the past, this container can reduce the seepage of oxygen and carbonic acid, can keep gas barrier properties in a long time, both made under higher temperature and also can keep gas barrier properties, simultaneously, the material that is adopted is the used identical resin of general laminated vessel.

Another object of the present invention provides a kind of new forming method, this method comprises the parison of a multilayer of injection mo(u)lding, the interior layer thickness of laminated vessel that makes institute's moulding by the way of using a kind of double-deck nozzle to inject into an interlayer is greater than skin, and the laminated vessel that can obtain having good trapping performance from the parison of above-mentioned this multilayer.

Therefore, the present invention can provide a kind of laminated vessel with and forming method, this container is made up of first kind of resin and second kind of resin, first kind of resin forms vessel, and second kind of resin has than first kind of trapping performance or resistance to heat that resin is big, second kind of resin is clipped among first kind of resin as interlayer, the said vesse body has three layers at least, it is above-mentioned interlayer, and by separated internal layer of above-mentioned interlayer and skin, because interlayer is offset to outer direction, so the thickness of the internal layer that forms is more much bigger than outer layer thickness, in addition, have under the situation of gas barrier properties at second kind of resin, the temperature of internal tank is weakened by the wall thickness of internal layer for the meeting that influences of interlayer, and has under the stable on heating situation at second kind of resin, then will make the container can be to sustain the high temperature in when bottling owing to the effect of thicker internal layer and interlayer.

The following describes accompanying drawing.

Shown in Figure 1 is the cross sectional drawing of using the part of the laminated vessel that the multilayer parison according to method moulding of the present invention obtains to cut open and amplify.

Shown in Figure 2 is cross sectional drawing according to the multilayer parison of moulding of the present invention.

Fig. 3 to Fig. 5 represents nozzle partial sum mould respectively, so that the job order of forming method of the present invention to be described:

Shown in Figure 3 is that the first kind of resin that forms multilayer parison body injected a part of cross sectional drawing;

Be the cross sectional drawing of nozzle upper part and exit portion shown in Fig. 4 A, second kind of resin that expression forms interlayer injected the middle situation of resin that forms vessel;

Be the cross sectional drawing of nozzle upper part and exit portion shown in Fig. 4 B, represent second kind of situation that resin is injecting;

Be the cross sectional drawing of nozzle upper part and exit portion shown in Fig. 4 C, represent first kind and second kind of situation that resin is injected into simultaneously;

Shown in Figure 5 is the situation that the moulding of multilayer parison finishes.

Fig. 1 represents a laminated vessel that is ampuliform, and it has three layers structure, and wherein internal layer 11 is formed by identical hot resin with outer 12, and interlayer 13 is then formed by the thermoplastic resin with good trapping performance.

The data of 4 embodiment according to the present invention, the thickness of interlayer 13 are less than outer 12 thickness, and move to outer 12 1 lateral deviations, so the wall thickness of internal layer 11 is more much bigger than outer 12 thickness.

The ratio of the thickness of internal layer 11 and skin 12 is preferably in more than 1.5: 1, and the big more then trapping performance of the thickness of internal layer is good more.

The top laminated vessel of saying 1 can be used the 2 usefulness blowings of multilayer parison or the orientation blow mollding method moulding of three-decker, in this multilayer parison, the resin that forms the parison body is separated into internal layer 21 and outer 22 by interlayer 23, internal layer has different thickness with skin, and interlayer then injects the sort of resin of saying previously by another resin and forms.

This multilayer parison 2 is to carry out injection moldingly with the double-deck nozzle shown in Fig. 3 and other figure, and this double-deck nozzle 3 has two coaxial passages, and exeterior passageway 32 communicates with spout 31, and internal channel 33 then is connected with the end of exeterior passageway 32.

Carrying out in the forming process of multilayer parison with general double-deck nozzle, the first kind of resin that forms parison is that the exeterior passageway 32 by nozzle injects moulds 4 and goes, but in the method for the invention, first kind of resin 5 injects from internal channel 33, and injects the resin 6 that forms interlayer from exeterior passageway 32.Preferably in such scope, it can make first kind of resin 5 be retained in the middle of the spout 31 of nozzle as fuse to the injection pressure of resin 6.

During injecting resin, at first inject first kind of resin 5 of right quantities through internal channel 33 in mould 4: in this case, for polyethylene terephthalate (below be called " PET "), the pressure of injection is approximately 65 kilograms per centimeter ², be approximately 3.5 seconds inject time, after this, injection suspends, and injects second kind of resin 6 from exeterior passageway 32, and the pressure during injection is 90 kilograms per centimeter ², be 0.1 to 1.0 second inject time.

The second kind of resin 6 that is injected when first kind of resin 5 stops to inject is to the skew of the outside of the cavity that is marked with first kind of resin 5, shown in Fig. 4 A.

Such result shown in Fig. 4 B like that, the part of first kind of resin 5 that injection is earlier entered is owing to the cooling effect of mould 4 forms superficial layer 5a and 5b, remainder then is retained in the there in this section the inside of the spout from internal channel 33 to nozzle 31 with the form of fuse 5c, this fuse 5c makes resin 6 can not enter the core of first kind of resin 5 from the center of nozzle spout 31, but comes along the circumferential surface distribution of fuse 5c through nozzle spout 31.

After having injected a period of time, re-inject first kind of resin 5, also inject second kind of resin 6 simultaneously.Be about 1.6 seconds the inject time of second kind of resin 6, and first kind of resin 5 is about 3.4 seconds the inject time after injection begins once more, and the resin of twice injection is all mobile between the superficial layer that first kind of resin 5 forms owing to cooling, shown in Fig. 4 c.Thus, outer surface layer 5b has removed and has formed outer surface layer 22 by second kind of resin 6 from first kind of resin, 5 theres of flowing, and its thickness does not increase.Interior surface layers 5a fuses together with the first kind of resin 5 that injects with second kind of resin 6, thereby has increased thickness, forms a thick interior surface layers 21.Final result has formed a multilayer parison 2 with three-decker as shown in Figure 5, its interlayer 23 deflection outer surface layers 22 1 sides.

Used ethylene-vinyl alcohol copolymer as second kind of resin 6 in the above in the injection molding process of being said.When interlayer 23 is when comprising the polyamide moulding of methoxy thing (methoxylene group), second kind of resin 6 can inject separately after the resin 5 that forms parison injects, after this, can inject first kind of resin 5 more individually, also can when injecting first kind of resin 5,6 injections of second kind of resin be entered.

But, no matter how the time of second kind of resin 6 injection arranges, first kind of resin 5 always at first injects from internal channel 33, then 6 injections of second kind of resin are entered, the internal layer 21 that is separated by second kind of resin, 6 formed interlayers 23 in the multilayer parison 2 is had than outer 22 much bigger thickness from exeterior passageway 32.

When the amount of second kind of resin 6 reduced, the thickness of interlayer 23 also can reduce naturally, but at this moment outer 22 thickness does not have great variation, and the thickness of internal layer 21 then can increase.

Like this, the thickness of internal layer 21 and interlayer 22 can be regulated mutually to improve the trapping performance and the resistance to heat of container.In some cases, the amount of second kind of resin 6 can reduce with the cost-cutting expense, because in general second kind of resin 6 to the first kinds of resin 5 is more expensive.

Below the trapping effect of carrying out three layers of container of the biaxial orientation that the orientation blow mollding moulding obtains with the conventional method of parison 2 usefulness at the bottom of the top sandwich tape of saying is listed in:

Embodiment and example relatively

Container types: the round-bottomed bottle that is used for carbonated drink

0.7 rise 26 grams

First kind of resin: PET:TEIJIN TR-8550

Second kind of resin: PA:MXD-6 nylon

The third resin: EVOH:KURARE EVERL

E-105

The machine that uses: ASB-50HT 107(is made by NISSEIASB)

Injectability: first kind of resin: 3,50 ounces (φ 38 spirals)

Second kind of resin: 1,0 ounce (φ 19 spirals)

The leak factor (every bottle) of oxygen and carbonate gas: the CC/2 kilogram, 24 hours,

1 barometric pressure.

The measuring equipment of oxygen seepage: MOCON two channel gas leakage measuring instrument

The measuring equipment of carbonate gas seepage: MOCON five-way road gas permeation survey meter

(measuring a container that is full of 4-volume lime soil)

Measuring condition: relative humidity: inside-100%RH,

Outside-65%RH,

Room temperature: 24 ℃

Keep a week.

Embodiment 1,2 and example 1 relatively

The structure of container: skin/interlayer/internal layer

PET/PA/PET

Embodiment 1 embodiment 2 comparative examples 1

Wall of a container thick (u)

Outer 80 59 182

Interlayer 38 39 41

Internal layer 143 170 53

Whole wall thickness 261 268 276

Layer thickness is than 1/1.8 1/2.9 3.4/1 in outer

Oxygen leak factor 0.110 0.092 0.136

The carbonic acid leak factor---

Embodiment 3,4 and example 2 relatively

The structure of container: skin/interlayer/internal layer

PET/EVOH/PET

Embodiment 3 embodiment 4 comparative examples 2

Wall of a container thick (u)

Outer 76 60 188

Interlayer 15 16 16

Internal layer 174 194 52

Whole wall thickness 265 270 261

Layer thickness is than 1/2.3 1/3.2 3.6/1 in outer

Oxygen leak factor 0.111 0.099 0.207

Carbonic acid leak factor 0.447 0.398 0.803

Can see too clearly from top embodiment that says and comparative example, the interior layer thickness of manufacturing according to method of the present invention is greater than the container of outer layer thickness, and the container that its trapping effect is bigger than the outer layer thickness of general structure has improved.

In addition, also can notice, if a heat-resisting laminated vessel uses heat stable resin to make the material of interlayer, such as polycarbonate, polyaryl polyethylene terephthalate (U-POLYMER) or materials similar, the container that so this internal layer is thicker will have the good heat endurance energy, and it is also can not produce thermal deformation under up to 85 ℃ temperature that such container had both made.

Claims

1, a kind of by at least three layers of laminated vessel of forming, make by the multilayer parison of injection mo(u)lding forming method with blowing or directed blowing, this parison comprises that first kind of resin forming its body and trapping performance or resistance to heat are higher than second kind of resin of first kind of resin, second kind of above-mentioned resin is among first kind of resin as interlayer, it is characterized in that: the thickness of above-mentioned interlayer is less than outer field thickness and be partial to above-mentioned skin, by above-mentioned interlayer first kind of above-mentioned resin is separated into internal layer and skin, interior layer thickness is 1.50: 1 or bigger with the ratio of outer layer thickness.

2, the laminated vessel said of claim 1, it is characterized in that: first kind of resin is polyethylene terephthalate, and second kind of resin is ethylene-vinyl alcohol copolymer.

3, the laminated vessel said of claim 1, it is characterized in that: first kind of resin is polyethylene terephthalate, and second kind of resin is polyaryl resin or polycarbonate.

4, a kind of manufacturing process of laminated vessel, use a double-deck nozzle with exeterior passageway and internal channel, its exeterior passageway links to each other with the spout of nozzle and internal channel is connected with above-mentioned exeterior passageway end, it is characterized in that forming first kind of resin injection of parison body to cavity from above-mentioned internal channel handle, the second kind of resin injection that forms interlayer in above-mentioned first kind of resin, be offset to skin in the interlayer forming process, therefore encircle into a multilayer parison that has three layers at least, to separate by the ectonexine that first kind of resin forms by interlayer, the thickness of internal layer is greater than the outer field thickness that is formed by same resin, above-mentioned multilayer parison is shaped to a laminated vessel with the method for blowing or directed blowing, and the thickness of its internal layer is more much bigger than outer field thickness.

5, the laminated vessel forming method said of claim 4, it is characterized in that: the internal channel of a certain amount of first kind of resin by double-deck nozzle is expelled in the cavity, suspend this resin of injection then, and the exeterior passageway by nozzle is with in first kind of resin of second kind of resin injection in the cavity, and then by first kind of resin of internal channel injection, inject second kind of resin simultaneously, stop to inject second kind of resin then, stop to inject first kind of resin to form the parison of a multilayer after a period of time.